Patent EP-A-3 192 discloses a band clamp fitting constituted by a band of metal wound on itself, of which the two ends are respectively provided with a radial fold, forming bearing point for tightening the clamp by means of a tool of the pliers type.
The radial fold of one of the ends of the band, preferably the end of the outer portion, is provided with a hook capable of passing behind the radial fold of the other end, during the clamp tightening operation, with a view to hooking thereon and thus maintaining the clamp fitting in its tightened position. On the other hand, the end of the inner portion of the band whose radial fold is preferably without hook, extends beyond said fold at least beyond the hook in the closed position of the clamp fitting.
Such a clamp fitting is largely used in industry, in particular in automobile construction, particularly for fixing a flexible pipe fitted on a rigid tube.
However, as the requirements of the art are becoming more and more severe, it appears essential to give the clamp fittings of the type in question a structure such that it may satisfy two apparently contradictory conditions.
In fact, without accepting a noteworthy modification of the radial pressure exerted by the clamp fitting on the clamped member, such as a rubber hose-pipe, the clamp fitting is now required, on the one hand, to be capable of elastic extension under the effect of the thermal expansions, which are sometimes considerable, of the clamped member and of its support, for example during operation of an engine, on the other hand, to be capable of elastic retraction if the ambient temperature becomes much lower than the temperature at which the clamp fitting was assembled, for example after the engine has been stopped in a very cold zone.
It is therefore an object of the invention to provide a clamp fitting of the type in question which satisfies these two contradictory requirements.